Type II diabetes mellitus accounts for 85-90% of the total number of diabetes mellitus, and its prevalence is increasing year by year, with more than 200 million patients worldwide, and its complications cause death and disability, seriously threatening the health and life of patients. However, all the above-mentioned medical treatments cannot ensure that the patient’s blood glucose returns to normal levels and cannot prevent the emergence and further aggravation of various diabetic complications. In recent years, analysis of clinical data of patients who underwent bariatric surgery revealed that gastric diversion surgery (GBP) and biliopancreatic diversion (BPD) for the treatment of obesity had a cure rate of over 90% for coexisting type II diabetes, while other non-diversion bariatric surgeries, such as adjustable banding gastric narrowing and reduction, longitudinal gastric banding shaping, etc., do not achieve significant results in the treatment of type II diabetes. Clinical data suggest that the weight loss of obesity after GBP or BPD is not synchronized with the reduction of blood glucose: early postoperative weight loss is not obvious when the reduction of blood glucose is obvious, thus suggesting that GBP or BPD has a unique therapeutic value for type II diabetes. The quality of surgical treatment of diabetes mellitus The change in glucose tolerance of patients is obvious before the effect of surgical weight loss is obvious; the change in blood glucose after surgery is also obvious in patients without obesity. The difference between the latter and the former is the “digestive tract diversion”, i.e. food no longer passes through the distal stomach, duodenum and part of the upper jejunum, but reaches the ileum earlier. It also reaches the ileum earlier. The mechanism of GI diversion surgery for type II diabetes is related to neuroendocrine modulation. Before diversion surgery, the upper gastrointestinal tract of diabetic susceptible patients is stimulated by food to produce “insulin antagonistic factors”, which causes insulin resistance in the body and is considered to be the main cause of type II diabetes. After diversion, the stimulation of the upper GI tract by food disappears or is reduced, and these factors are no longer or less frequently produced, resulting in the reduction or disappearance of insulin antagonism in type II diabetes. The diversion procedure allows undigested or incompletely digested food to enter the ileum earlier, which can cause the body to produce factors that increase insulin action, such as insulin-like growth factor-1 (IGF-1), contributing to lower blood glucose. The factors that may be involved in the occurrence and development of type II diabetes that are closely related to the active factors are leptin (Leptin), IGF-1, glucagon-like peptide-1 (GLP-1), as well as hyperglycemic hormone and gastric inhibitory peptide. These factors affect the regulation of plant nerves and brain function. The field of neuroendocrinology is a hot topic for research on the pathogenesis of type II diabetes. Although the mechanism of GBP surgery for type II diabetes is not well understood, the efficacy in coexisting type II diabetes is surprisingly good, and the case sample is large, with normal blood glucose maintained after long term follow-up with discontinuation of all hypoglycemic drugs and no dietary restriction. Clinical studies have shown that GBP can be used to treat not only those who are obese, but also those who are not obese with type II diabetes. As a result, the technique has been approved by the FDA, thus opening a new chapter in the surgical treatment of type II diabetes. Modalities and techniques for surgical treatment of diabetes GBP surgery can be performed using either a microincision approach or a minimally invasive laparoscopic approach, both of which have the same therapeutic effect, but the latter is less invasive. With the open approach, the surgery is mainly focused on the bottom of the stomach, so the incision is made in a small 6-7 cm longitudinal incision in the middle of the upper abdomen. If minimally invasive surgical techniques are used, using digestive tract closures and anastomoses, as long as four small 0.5-2.0 cm holes are made in the abdominal wall, it is not only less invasive and aesthetically pleasing, but also saves time and ensures closure and anastomosis. The procedure can be completed in 45-60 minutes, and GBP is not a major surgery and does not require harsh technical conditions and has low surgical complications. Indications and contraindications for surgical treatment of diabetes mellitus The selection of patients with type II diabetes mellitus for GBP surgery is a clear indication for surgery. It should be clear in the preoperative examination that the patient’s serum insulin and C-peptide values are elevated or at normal values for GBP to be suitable. If these two indicators are reduced, it often indicates islet insufficiency or failure, which should be the diagnosis of type I diabetes or late transformation of type II diabetes into type I diabetes, and these conditions are contraindications for GBP surgery for diabetes. Persistent skin infections and coexisting hypertension are not contraindications to surgery. In past clinical data, these coexisting conditions resolved or resolved significantly after surgery with improvement in blood glucose.